Smoking research and intervention efforts have substantially neglected middle-aged and older adults, with older women who smoke particularly underserved. Yet, cigarette smoking is a significant cause of morbidity and mortality among women in midlife and aging, and the hazards of smoking for women increase with age. Although adult smoking is maintained in significant part by nicotine addiction, important aspects of women's smoking in midlife and aging may involve psychosocial factors that are amenable to intervention. Depression in particular plays a significant role in maintaining adult smoking, although much less is known about the role of depression among older smokers. The greater prevalence of depression among women makes depression an important concern in women's health in midlife and aging. Although previous research has focused on clinical depression, increasing evidence indicates that sub-clinical levels of depressive symptoms, which are prevalent among women in midlife and aging, are also linked to smoking. However, the lack of a comprehensive model of social contextual and behavioral factors that affect smoking through depression or that mediate between depression and smoking hinders interventions to reduce smoking among women in later adulthood. The Surgeon General's report on women and smoking calls for longitudinal research on depression and smoking in women across the adult lifespan. This project will examine: (1) the relationship of depressive symptoms to smoking among middle-aged and older women, (2) the predictive role of social contextual and personal factors related to depression and smoking, and (3) demographic and health-related factors that make subgroups of women especially vulnerable to depression-related smoking. In this project we will conduct secondary analyses of data from the Women's Health Initiative (WHI) Observational Study. The WHI Observational Study followed 93,676 women between the ages of 50 and 79 at enrollment for up to 8 years. The WHI Observational Study presents a unique opportunity to examine the link between depressive symptoms and smoking in a large diverse sample of postmenopausal women, with psychosocial and health-related data available at multiple time-points. Our research team will approach the study from complementary perspectives. This project is innovative in its unique focus on depression and smoking in middle-aged and older women, its use of the WHI Observational Sample to follow a socioeconomically and ethnically diverse sample longitudinally, and it's modeling of risk and protective factors in the depression-smoking relationship among women in this population. Consistent with Healthy People 2010 objectives to reduce adult smoking, this project will have a positive impact by providing a conceptual foundation for effective smoking reduction interventions with middle-aged and older women. PUBLIC HEALTH RELEVANCE: Cigarette smoking is a significant cause of morbidity and mortality among women in midlife and aging. Reducing adult smoking is a central goal of Healthy People 2010. This project uses data from the Women's Health Initiative to investigate the relationship of depressive symptoms to smoking among middle-aged and older women.